CLAY AND SHALE. 129 
the public road for several miles, also in the neighborhood of Zollars- 
ville, on Pike Run, throughout the borough of Deemston, and on 
South Branch of Pigeon Creek. On North Branch of Pigeon Creek, 
Mingo Creek, and farther north the sandstone is of little importance, 
being usually either shaly or replaced by shale. In the vicinity of 
Washington and Houston and in general over the northwestern por- 
tion of the quadrangle the sandstone is poorly developed or missing. 
In general, it may be said to be well developed in Greene and southern 
Washington counties, but to die out toward the northern part of Wash- 
ington County. 
It is generally flaggy to shaly, but here and there rather massive. 
It is probably too friable to be of much value, but it is said to have 
been used in Greene County for building. 
OTHER SANDSTONES 
The only sandstone quarry of any account in the Amity quadrangle 
is between the National pike and the railroad tunnel a mile east of 
Washington, about 130 feet above the Upper Washington limestone 
outcropping at the entrance to the tunnel. A fair-sized quarry is 
operated here by the Hallam Construction Company, the stone being 
used for curbing and bridge construction and to a limited extent in 
buildings. The sandstone lies a few feet above a bed of limestone 
reported in a well and is a good, hard, massive rock. The same bed 
has been prospected in other parts of the quadrangle. 
Other sandstone beds of variable character are distributed through 
the Dunkard group and some of them may prove to be of value. 
CLAY AND SHALE. 
Two classes of material suitable for making brick are found in this 
territory. These are clay and shale, the former being a surface deposit 
and the latter making up a large proportion of the hard rocks. 
CLAY. 
In this quadrangle there are both residual surface clays and deposits 
in the stream valleys. The residual clays are of low grade and are 
abundant. The stream deposits are not so widely distributed, but 
are available at several points. So far as known, they have not been 
used in the quadrangle, but just beyond the northern border, between 
Houston and Canonsburg, is a small brickyard operated by the Alex- 
ander Brick Company. The clay used here is a tough silty layer of 
buff color capping a gravel terrace of the Carmichaels formation. The 
material is somewhat gritty to the teeth, but contains no pebbles. 
Below this bed occurs from 6 inches to 3 feet of gravel, and underlying 
that 8 feet of hard clay is reported. The lower bed is not known to 
Bull. 300—07 9 
